This invention relates to welding of lead battery parts together, especially intra- and inter-cell connections, and is effective for welding relatively thin lead battery components to relatively thick lead battery components utilizing a modified arc casting technique.
Traditionally, lead parts in electrochemical cells in batteries have been joined by either a burning process or a gas welding process. An improved process employing arc welding with an inert-gas-shielded non-consumable electrode is disclosed in U.S. Pat. No. 3,806,696 to Young et al. In the Young et al method, an ingot-like mold of good thermal conductivity, arc resistance, and other suitable properties is positioned around the parts to be welded, the electrode arc is struck and passed over the lead parts while simultaneously oscillating the arc back and forth across the surface to be welded. The patent to Young et al discloses striking the arc short of the weldable surface and then transversely oscillating the arc over such surface. It has also been common in other processes using TIG (tungsten-inert-gas) welding to oscillate the arc, either mechanically or magnetically laterally over the surface to be welded, as shown for instance in U.S. Pat. No. 3,646,309 to Smith, Jr.
While the Young et al process was found to be very reliable for welding expanded mesh lead current collector tabs to solid lead post connectors, it was found that the process was not nearly so reliable for welding solid current collector tabs to the lead posts; in the case of welding the solid current collector tabs, the welds were nonuniform and resulted in an intolerably high rejection rate.
It is an object of the present invention to overcome problems inherent in prior art methods for joining lead parts together in a battery construction, and to provide a relatively pore-free, low internal impedance weld using a very rapid process with a minimum or total absence of moving parts.